The concept of food security has evolved greatly over the past fifty years. The most widely accepted definition is that of the World Food Summit (1996), amended in 2001 by FAO , which incorporated nutritional and cultural dimensions and recognized the multi-dimensional character of food security:

“Food security exists when all people, at all times, have physical [and social] and economic access to sufficient safe and nutritious food that meets their dietary needs and food preferences for an active and healthy life”.

World Food Summit, 1996 and State of Food Insecurity Report, FAO 2001.

This definition features four important dimensions or “pillars” that are central to the concept — including not just availability and access but also utilization (referring to nutritional uptake) and stability (referring to the constancy of the other three dimensions). These four components of food security interact in a sequential manner:  First, food must be available; then households must have access to it; they must use it appropriately; and finally, the whole system must be stable, i.e. food must be available, accessible, and used appropriately throughout the year by all - see more details in 2.3.1 below. 

The four dimensions of food security are also recognized—either explicitly or implicitly—within legal interpretations of the right to food (including article 11 of the International Covenant on Economic, Social and Cultural Rights (ICESCR) which came into force in 1976 and General Comment 12 of The Committee on Economic, Social and Cultural Rights in 1999, which specifically mentions food availability and accessibility, including both economic and physical access. It also references dietary needs, which equates to utilization, as well as the need for states to ensure vulnerable population groups and individuals to receive adequate food even in times of severe resource constraints, which equates to stability. A Special Rapporteur on the right to food was established by the Commission on Human Rights in April 2000, and the mandate was endorsed and extended by the Human Rights Council by its resolution 6/2 of 27 September 2007.

In assessing food security, particular attention is also given to the economic, social, and environmental dimensions (in light of the current climate change related shocks and implications).